If Yawning Has a Regulatory Mechanism Similar to Breathing,then Which

Multiple Choice

If yawning has a regulatory mechanism similar to breathing,then which of the following is TRUE?

A) Athletes should yawn more when exercising compared to when they are not exercising.
B) Tibetan mountaineers yawn more when they are walking compared to when they are standing still.
C) People adapted to lower altitudes should yawn the same amount when they are at high altitudes.
D) Athletes who have trained at high altitudes should inhale a greater volume of air when yawning compared to those who have trained only at low altitudes.